More and more devices are being replaced with autonomous and semiautonomous electronic devices. This is especially true in the hospitals of today with large arrays of autonomous and semiautonomous electronic devices being found in operating rooms, interventional suites, intensive care wards, emergency rooms, and the like. For example, glass and mercury thermometers are being replaced with electronic thermometers, intravenous drip lines now include electronic monitors and flow regulators, and traditional hand-held surgical instruments are being replaced by computer-assisted medical devices.
These electronic devices provide both advantages and challenges to the personnel operating them. Many of these electronic devices may be capable of autonomous or semiautonomous motion of one or more articulated arms and/or end effectors. These one or more articulated arms and/or end effectors each include a combination of links and articulated joints that support motion of the articulated arms and/or end effectors. In many cases, the articulated joints are manipulated to obtain a desired position and/or orientation (collectively, a desired pose) of a corresponding instrument located at a distal end of the links and articulated joints of a corresponding articulated arm and/or end effector. Each of the articulated joints proximal to the instrument provides the corresponding articulated arm and/or end effector with at least one degree of freedom that may be used to manipulate the position and/or orientation of the corresponding instrument. In many cases, the corresponding articulated arms and/or end effectors may include at least six degrees of freedom that allow for controlling a x, y, and z position (collectively referred to as translational movement) of the corresponding instrument as well as a roll, pitch, and yaw orientation (collectively referred to as rotational movement) of the corresponding instrument. To provide for greater flexibility in control of the pose of the corresponding instrument, the corresponding articulated arms and/or end effectors are often designed to include redundant degrees of freedom. When redundant degrees of freedom are present it is possible that multiple different combinations of positions and/or orientations of the articulated joints may be used to obtain the same pose of the corresponding instrument.
It is often desirable for the surgeon or operating room staff to move a patient on an operating or surgical table relative to the manipulator arms of a computer-assisted device being used as a surgical manipulator assembly in order to improve or optimize access to, or visualization of, the patient's internal anatomy. For example, a surgeon may wish to perform a gravity-assisted retraction of an organ during a surgical procedure. Because the patient's organs will move as the surgical table is tilted, for safety the surgical instruments are removed from the patient prior to moving the surgical table. Then, in many conventional teleoperated surgical systems, to perform such a retraction, the manipulator arms must be undocked from the cannulas coupling the patient to the manipulator arms so that the body openings where the instruments are inserted into the patient can safely move, the surgical table must then be moved into a new position estimated to be suitable for retraction of the targeted organ, and then the instrument reinserted into the body openings. This method can be time consuming and cumbersome. Furthermore, this process may involve several iterations, because the endoscope is generally also removed from the patient before the table is moved to improve safety, such that visualization of the surgical workspace is lost and the new position is typically an educated guess, which may or may not be accurate or sufficient to properly perform the retraction. To avoid repeated iterations, physicians often “overcorrect” and select positions and orientations that are steeper than necessary to ensure that the desired gravity-assisted retraction occurs. This overcorrection may lead to patient safety problems, because certain orientations, such as a head down orientation of the patient, may be poorly tolerated by a patient, and particularly by larger patients who often have difficulty breathing in such an orientation. In addition, because the instruments are removed from the patient and the manipulator arms are removed from the cannulas, the instruments cannot be used by a physician to assist with the retraction, such as may be done in a traditional laparoscopic procedure.
Accordingly, it would be desirable to allow for repositioning of the patient and or articulated arms while the articulated arms are connected to a patient. It would also be desirable for a user to maintain some control over the articulated arms as the patient or the arms are being repositioned. The systems and methods disclosed herein address these problems along with other problems.